1. Field of the Invention
The present invention relates to an apparatus and a method for adjusting a temperature compensated quartz oscillator which are capable of obtaining a smooth frequency characteristic in a wide temperature range of -20.degree. C. to 60.degree. C.
2. Description of the Related Art
Conventionally, a quartz oscillator used in, for example, a portable telephone terminal and the like is formed as a module structure, and the oscillator itself is provided with a temperature compensating circuit for directly compensating a frequency shift due to the temperature of the quartz oscillator so as to stabilize the frequency in a wide temperature range through hardware. Namely conventional module has a circuit directly compensating a temperature characteristic within the module, and without controlling a CPU. Accordingly, it is thought that the quartz oscillator of this pattern conventionally required only frequency adjustment at normal temperature, and did not require adjustment concerning the temperature characteristic.
However, the above-described conventional temperature compensated quartz oscillator does not necessarily operate to accurately compensate the temperature characteristic of the quarts oscillator due to the variation of a temperature compensating circuit and the quartz oscillator of the oscillator, so that the yield in production has been poor, resulting in higher price.